This invention concerns the sulfinate-initiated addition of a fluorine-containing iodide to an olefin.
Several types of reactions are known in the art for addition of a fluorine-containing iodide to an olefin. For instance, see in this regard: Sheppard et al., "Organic Fluorine Chemistry", Benjamin, New York, 1969, pages 189 to 194 and Table 6-1. Other representative reactions are summarized hereafter:
Moore, J. Chem. Eng. Data 9, 251 to 254 (1964), UV irradiation; PA1 EPA 43,758, electrochemical initiation; PA1 EPA 43,757, mercuric salt catalysis; PA1 U.S. Pat. No. 4,058,573; U.S. Pat. No. 4,144,244; U.S. Pat. No. 4,436,141; free-radical initiation employing azo compounds and peroxides; PA1 U.K. No. 1,319,898; Burton et al., Tet. Letters 5163 (1966); and Brace, J. Org. Chem. 44, 212 (1979); metallic compounds and/or amines; and PA1 Feiring, J. Fluorine Chem. 24, pages 191 to 203 (1984), addition of perfluoroalkyl iodides to norbornene in the presence of nitronate ions and thiolate ions with concurrent formation of major amounts of side products. PA1 R.sub.f is a perfluorinated primary or secondary C.sub.1 to C.sub.18 moiety which can be aliphatic or alicyclic, can be substituted, or, except for the C.sub.1 moiety, internally interrupted by any group that will not react with the sulfinate salt; PA1 R.sub.1 to R.sub.4 are, individually, H or a substituted or unsubstituted C.sub.1 to C.sub.16 moiety, or R.sub.1 to R.sub.4, taken together, form a mono- or bicyclic aliphatic ring, the atoms directly linked to olefinic carbon atoms being aliphatic or alicyclic carbon; PA1 R.sub.5 is substituted or unsubstituted C.sub.1 to C.sub.18 moiety; PA1 m is 1 or 2; and PA1 M is a cation selected from alkali metal, ammonium, quaternary ammonium or tris(dialkylamino)sulfonium.
Japanese Application 57-085327 discloses addition of pentafluoro-3-iodopropene to ethylene under ultraviolet irradiation to form 1,1,2,3,3-pentafluoro-5-iodopent-1-ene.
In contrast to the methods practiced by the prior art, the sulfinate-initiated process of this invention can generally be run at lower temperatures, for shorter times, usually forming the desired product in good yield. The process can be scaled up simply, and expensive equipment such as high pressure, UV, and electrochemical equipment is not needed. This process also avoids the need for toxic, explosive, or corrosive initiators such as peroxides, azo compounds and transition metal salts.
Finally, Kondratenko et al., J. Org. Chem. 13, 2086 (1977) disclose that aromatic sulfinic acids react with perfluoroalkyl iodides in liquid ammonia under UV irradiation to give aromatic perfluoroalkyl sulfones. No mention is made of conducting the reaction in the presence of olefins to make fluorinated iodides.